High Yield GIT Bacteria and Worms

8/13/2019 High Yield GIT Bacteria and Worms

1/11

Bacterial GIT IV: Session 51 (Melu)

1. Describe the conditions leading to antibiotic associated colitis and the antibiotics that may cause this state.

Pseudomembranous colitis (PMC) classic example of an antibiotic treatment-induced disease.

ass w/ antibiotic use o!ergrowth of normal flora

o ex. clindamycin" cephalosporins" ampicillin" some anti#neoplastics

$$ Clostridium Difficile

%(&) rod' naerobe' P*+, former (subterminal)

-hen things go wrong (!arying degrees of pathology)

a) Diarrhea w/ lower ab cramping nosystemic symptoms

b) e!ere colitis w/opseudomembrane profuse diarrhea" pain system symptoms fe!er" malaise" dehydration

c) Classic pseudomembranous colitiso symptoms same as se!ere

o elevated yellowish plaques 1-10 mm over inflamed regions of mucosa

o psudomembrane 0 fibrin mesh of necrotic cells" PMs" monocytes" +2

3. *utline the disease process of pseudomembranous colitis

Ma4or predisposing factor 0 D5+6P75* *8 *+M9 %67 89*+

o coloni:ation/o!ergrowth of C difficile release of toxins

o ;1s

o symptomatic carrier

D? of T!I" best

o ,5 most reliable detection of toxin of specific proteins in feces is best tool for disease etiology

o (#) tests do *7 rule out PMC dx

7? fluid/electrolytes

o admin ,- antibiotic

#ancom$cin (superior)"

metronida:ole

Complications

o spores +,577 to antiobiotics' some pts will relapse" some multiple times

tory if you isolate bacteria (w/ clindomycin) and infection not going away /or getting worse... logically thin>Clostridium built a resistance to Clindo... actually" they are all sensiti!e to clindo" but *M,7@5% ,9, is in the mix...could be another player" or the toxin still causing symptoms

*, resistant strain can protect the rest of the Clostridiums... or doesnAt ha!e to be Clostridium remember

they donAt li!e in isolation...


2/11

B . %i!e the is the mec%anism(s) e&idemiolo'ical featuresof food poisoning caused by taphylococcus" 2. cereus" and Clostridium perfringensand the conditions under which each is most li>ely to occur.

%eneralClinical

Manifestationsirulence 8actors ,pidemiology D? 7?/Pre!entio

Clostridiumperfringens 7ype

Common cause ofacute food bornediarr%ea (S)

%(&) rodpore 8ormer*motile

naerobe

S%ortincubation*+,IonsetSe#erewaterydiarrhea

b cramping7E "fe#er"#omitin'*+,I reco!ery ;1day

.nterotoin(ileum)# s$n durin's&orulation(defense againstengulfment)

Common gut flora (ppl animals)#contaminated meat"poultry" gra!y notcoo>ed enough todestroy spores s&ores 'erminate iffood is left out0IG0 dosem/o

o fe!erDetectAn of 9+%,Fs in food/fecesG1in highosmotic stressen!irons.

Pre!ention8ood handlers staph infectAn(H


3/11

Intro to ,arasites: Session 53 (Melu)

1. 9ist the parasitic diseases and respecti!e causati!e agents (scientific names).

*bstruction

scaris (intestinal bloc>age)

o bile duct (only ta>es 1 worm)

o %5 (multiple worms)

7issue Destruction

Plasmodium (malaria)

o destroys +2Cs

o reNuires ;Hworms

o microcytic anemia

Pressure ,chinococcus granulosus

o hydatid disease (cyst) grows in sensiti!e organ (C)

@ost immune response

eosinophilia"

tissue destruction

hypersensiti!ity

granuloma rxn

wuchereria bancrofti

3. isually identify the agents from their microscopic structures (eg" cyst" tropho:oites" eggs" etc).see each lecture for pictures in charts...

B. 9ist the infecti!e stages (ie" how the person contracts the parasitic infections).

5ngestion ,ggs/cysts 8eces contaminate water food

Direct >in Penetration 9ar!al tage 5n!ades thru s>in hoo>worm" schistosomes

Direct P3P exual contact 7richomonas

rbobone sporo:oites 2ite from arthropod MosNuito in4ectingsporo:oites into human

. Describe the pathogenicity" !irulence factors" and clinical presentation of each disease.see each lecture chart for descriptionH. Describe the treatment options for each disease.

Euinolines Euinine" chloroNuine"primaNuine" mefloNuine

5nterfere w/ D replication inparasite

Plasmodium

rsenic ntimonial Cmpds odium stibogluconate 2ind to sulfhydryl grps on proteins en:s

9eishmania

8olic cid 5nhibitors 7rimethoprim" sulfonamides 7arget the synthesis of folic acid forpurine biosyn

Cyclospora

itroimida:oles Metronida:ole 5nhibit D syn thy D al>ylation %iardia" trichomonad (7D)" amoebas

Ben:imida:oles Mebenda:ole" abenda:ole7hiabenda:ole cattle

5nhibits tubulin polymeri:ation microtubule formation

scarid@oo>worms

Paralytic gents Pyrantel pamoate" pipera:ine"i!ermectin

tim neuromm paralysis scarid/roundworms(Kexcretion/>illing)

Pyra:inoisoNuiniolines Pra:iNuantel lter balance of intracell Ca3& which

causes titanic mm contraction alterations in tegument increase>illing by host immunity

5ntestinal tapeworm (gi!en to dogs)

7etracyclines 7racycline" doxycycline 5nterferes w/ protein synProphylactic for malaria

Plasmodium" 2alantidium

L. Contrast how a parasitic disease is diagnosed bacterial disease.see each lecture for DX.

J. *utline control measures" pre!entati!e steps" and the epidemiology of each disease.see each lecture for these...


4/11

HB"H

or'anism disease &at%o&%$s ia'nosis (&ic) e&idemiolo'$ Treatment

Giardia lambliaProtozoan singlecell flexible!

cyst o!al"hyaline/chitin wall"8nuclei1 cyst 0 3 trophs

Trophozoite:bilobed teardropadhesi!e disc flagella"3 nuclei

%iardiasis water$ diarr%ea(intermittent)

cyst does not cause illness

dose not in!ade or destroy+2Cs

cysts (feces)Cyst ingestedtroph (duodenum)fecal/oral

$$ ;3 wee> inoculatory period5nfecti!e dose ;1


5/11

eggs

L1

L2

L3

L4

adult

Blastoc$stosis Distractor answerI

9%i&worm and +scarids: Session 55 (Melu) -- nemotodes

1. 9ist characteristics of nematodes. sessions HH and HL roundworms

emotodes 0 roundworms

o *7 all parasitic

o long" cylindrical" tapered" unsegmentedo 7ube w/in a tube

uter tube > cuticle" hypodermins" mm" nn" , (secretory) system

Inner tube > complete digesti!e reproducti!e system

In between > pseudocoelomic space filled w/ noncompressible fluid hydrostatic s>eletom

circulatoryQ system

o " ?.GS

o 9ife Cycle egg" 9ar!al stages" adult stages loo> the sameOseparated by Moltin'I (i.e. li>e a sna>e)

Caenorhabditis elegans is popular model system

*7,scaris suum large roundworm of pig intestines

similar to . lumbricoides

o but many differences

humans can be infected accidental host

9ower Rield

7richuris other helminthes tend to

stimulate 7h3 response 5l" 5lH" eosinophils

suppress 7h1

o can affect susceptibility to other infections

induce 7 reg populations

0$'iene 0$&ot%esisearly exposure to helminthes reNuired for proper tuning of immune system to a!oid damaging 7h1 responses seen in

autoimmune disorders

o Correlation between what youAre exposed to early in life can determine how your immune system de!elops.


6/11

%eneral/7ransmission

5nfecti!e/diagnosticstages

,pidemiology 7ypical eggsClinical

Manifestations7?/Pre!ention/

trol

7richuris truchuria

0uman9%i&worm

Direct life cyclew/ointermedhost/!ector

ecal/oral route

,ggs de!elop insoil

;B wee>s#warm" moist soil

promotesde!elopment

Mature femalesBH#H< mm

Mature malesBled fish

(Uapan" Pacificcoast of . meri"etherlands)

donAt forget aboutimportsI

,gg stage w/in fish"not human

w/in @*6+ ofingestion

ab pain" nausea"

!omiting9ar!ae get coughedup

5f lar!ae get intointestine

.osino&%ilic'ranulomatousresponselasts

;1#3 wee>sA similarto CrohnAs d:

8R5 gastoscoexamination

7issue remo!remo!al of lar!

(surgical)

Pre!ention (8R8ree:e for 1 we

or8lash 8ree:e

G1H hrs

Tric%uria: +scarites:


7/11

+nisa7is


8/11

Medicall$ Im&ortant *oundworms: Session 5C (Melu) -- nemotodes

emotodes 0 roundworms

o *7 all parasitico long" cylindrical" tapered" unsegmented

1. %i!e the scientific names and their corresponding diseases.

trongyloides stercoarlis asthma" s>in infections

ecator americanus/ncylostoma duodenale pneumonitis" hypochromatic anemia" s>in infections

ncylostoma bra:iliense/ncylostoma caninum Pruritic" erythematous" serpignious lesion

,nterobius !ermicucularis Pruritis ni worms in perianal folds

*7, 7hin> ,7 roundworms ,nterobius scaris 7richuris ##G we eat/ingest the infecti!e stage (embryonated egg)

5D/5ETa&eworms

trobila 0 flat body/ribbon li>eProglottis 0 segments

contain reproducti!e organs (hermaphroditic)

%ra!id proglottis fully de!eloped eggs

,C@ segment/proglottis contains eggsI

colex 0 mainly for attatchment bothria" suc>ers" hoo>s" or spines7egument

li!ing tissue w/ high metabolic acti!ity

Microtric%es A K absorpti!e areaOsimilar to micro!illi in gut (worm turned inside out)

Muscular system circular T.*/lon'itudinal I"".*

"odigesti!e system nutrients are absorbed

9ife Cycle

,gg found in fecesof definiti!e host (adult worm releases eggs)

Metacestode0 lar!a found in intermediate host

o Plerocercoid ( sparganum) 0 solid body

Diphyllobothrium

o Cysticercoid 0 solid body but lac>s bladder

Hymenoplepsis

o Cysticercus

bladderworm 0 taenia

o @ydatid cyst contains protoscolices

dult worm found in definiti!e host

5nfecti!e tage either ,gg or Metacestode (species dependent)7x PraiNuantel (dissol!es the scolex)same tx for dogs cats" so if need immediate" 4ust got to petsmartI

Metacestode pics


9/11

ession HL%eneral/

7ransmission5nfecti!e/diagnostic

stages,pidemiology Pathophysiology

ClinicalManifestations

7?/Pre!entiControl

Stron'$loidesstercoralis

(Infecti#e sta'e)

ecal/oral

9ife cycle isfacultati#ecan completeits life cycle insoil/en!iron

*rw/in host

dult 0 small worm

Voonotic d:

Infecti#e sta'e> filariform lar#a

SPenetrate intact

s7in@

,nter !enous orlymph

SPassi!ely

transported tolun's

S2rea> into al!eoli

@Migrate to

trachea/swallowedS

(attaches molts)dult reside insmall intestine

#>in penetrance oringestion of lar#a#transmammarypossible

ss. w/ TFcom&romised/+IS

Brdworld countries

dults produce eggshatch

r%abditiform lar#a&assed in feces >

dia'nostic T@

6utaneous:#5n!asion !ia s>in

,ulmonar$:#migrates thru lung damage tissue

GI,nteritis/eosinophilia

0$&erinfectnautoinfectAn incompromised pts

6utaneous:# light hemorrhage swelling# Pruritic lesion(6ree&in' eru&tion

W site of entry)

,ulmonar$:# produces intenseburnin' in c%est#hea!y infectAn #G&neumonitis

-- ass w/ ast%maTF

GI:,nteritis/eosinophilia

#Pre!ent feccontaminati

#,ducatio

D*C i!erme*r

72V 0thiobenda:omostly usedcattle indulots of emes

(DonAt respowell to

albenda:olemebenda:o

"ecatoramericanus

+nc$lostomaduodenale

ecal/ral

0H9*Mtout worm

2uccalCapsule

. americanus0 cuttin'

&lates. duodenale 0

lar'e teet%

Infecti#e sta'e>filariform lar#a

SS7inlun'GI

route(see abo!e)

$$eunum$$

7ime 1 w>

9i!e ;1#H yrs

7ropical/ubtropical-arm" Moist oil

Se'mented .''embryonatAn ;1#3days rhabditiform lar!afeeds on feces >dia'nostic > .GG

6utaneous:#Creeping eruption/ground itch pruriticlesion) ## anemia

,ulmonar$:#migrates thru lung damage tissue

GI:blood loss !ia

feeding on mucosaltissue (lacerations)

6utaneous:

,ulmonar$:,neumonitis

GI:0$&oc%romicanemia*ther ymptoms# protein deficiency#pot belly#dry s>in/ dry hair#mental dullness#heart failure#death#,osinophilia possible

!oid barefo

Pre!ent feccontaminati

,ducation

Mebenda:oPyrantelpamoate

orD*C

albenda:o

ncylostomabra:iliense

ncylostoma

caninum

6utaneous

lar#a mi'rans@

igrates thrus!in

@umansaccidental hostsGS/cats

Infecti#e sta'e>filariform lar#a

SS7in mi'ration

Puerto +ico" 8loridaouthern6..

ecalcontamination

&er&etuates lifec$cle

Pruritic"

erythematous"serpignious lesion

Cutaneous

Creeping eruptions7hiabenda:

(72V) topic5!ermectin

D*% C7

,nterobius!ermicucularis

,I"9*M

mall worm

,3,transmission

@all members of

householdshould be tx.

8ecalcontamination

Can be airborne

Infecti#e sta'e> .GG

S5nfecti!e in L hrs

Swallowed

hatches induodenum

SMolts twice

SMatures in

eunum/ileum

7ime 1H#B daysS

ttach to ileocecalbut can wander

8lat on one side"round on other

"T:oonoticII

8ound soiledfingers/nails'

clothing' bedding"curtains" carpets"

dust

Children X13 yoPoor hygiene

8reN.underrated

Minute ulcerations ofintestinal mucosa

8emalesmigrate

w/in lg intestine to&erianal s7in Tdia'nostic > .''

SMigration triggered

by lower body tempduring sleep (child)

SI.after expelling

eggsMales I.after

mating

9ife #L w>s

,ruritis +ni5rritation discomfort

b/c female womrsdeposit eggs in

perianal folds

Pt scratches" resultingin bleeding infection

,ggs are !eryadhesi!e fix to

tissue

Most infections 0asymptomatic

7x symptomsince wormself limiting

D?

T6ello&%ata&e eggstic> to tap(!iew micro

D*C pyranpamoate

mebenda:oalbenda:o

(eggs *7 >by drugs tx

3#B w>s)


10/11

ession HJ%eneral/

7ransmission5nfecti!e/diagnostic

stages,pidemiology Pathophysiology

ClinicalManifestations

7?/Pre!entiControl

asciolo&sisbus7i

Giant intestinallu7e

Large/Oval

In'estion:Infecti#e sta'e> Metacercariae

(of water c%esnut)@

dultS

ttaches to smallintestine

ia'notic> e''s in feces

1stintermed host059

S6entral/Sout%east

+siaChina" ietnam"

7hailand

*eser#oir %osts:Pigs" dogs" rabbits

w/ water chesnuts

,gg 0 Dx

light infections asymptomatic

hea!y infections diarrheaenteritisintestinal obstructioneosinophilia

pre!entcontaminatio

food/wate

Control snail

ascioloa %e&atic

S%ee& ?i#er lu7e

Large/leaf-

shaped

In'estion:Infecti#e sta'e> Metacercariae(of watercress)

@+dult

@9i!es in bile duct

@Maturation B# monthsia'notic

> e''sin feces

1stintermed host059

S(9orldwide)

,urope/ middle ,ast"sia

S*eser#oir %osts

heep/Cattlew/ watercress

,gg 0 Dx

,seudofascioliasispt recently ingested

infected li!er(pt is *7 actuallyinfected w/ flu>e)

+cute ,%ase:lu7e is mi'ratin':ab painhepatomegaly8e!eromitinDiarrhea6rticaria,osinophila

6%ronic:lu7e in Bile uctperiodic biliaryobstruction inflammation

7riclabenda:or bithiono# ma$ not

res&onds &ra4iJuant

5mpro!edsanitation

pre!entcontaminatio

food/wate

Control snail

6lonorc%issinensis

6%inese ?i#erlu7e

Small

Infecti#e sta'e> Metacercariae

(of fresh water fish)S

dult@

9i!es in sm/medbilar$ ducts

@Maturation

1 month

ia'notic> e''sin feces/

duodenal as&irate

1st intermed host059

S,ndemic areas of

+siaTorea" China"

7aiwan" ietnam(onendemic 0

+sian immi'rants)S

*eser#oir %ostsdogs" cats" fish#

eating mammals inendemic areas

Egg = D

Se#ere:8e!er

,pigastric pain@epatomegaly

Uaundice

In#asion of GallBladder:

CholecystitisCholelithiasis

5mpaired li!er fnx

7E ass w/c%olan'iocarcinoma

Pra:iNuant5mpro!edsanitation

pre!entcontaminatio

food/wate

Control snail

,ducation wraw/uncoo>

fish

0etero&%$es%etero&%$es

Minute intestinallu7e

small

Infecti#e sta'e

> Metacercariae(of fresh/brac>ish

water fish)@

dultS

ttaches to smallintestine

ia'notic> e''sin feces

1st intermed host059S

,gypt" Middle ,ast"8ar ,ast

S*eser#oir %ostsdogs" cats" fish#

eating mammals birds in endemic

areas

Intestinalb painDiarrhea

M$ocarditis if eggsreach heart

,ggs can get intocirculation to brain.

Pra:iNuant

5mpro!edsanitation

pre!entcontaminatio

food/wate

Control snail


fish

Meta'onimus$o7o'awai

Small

Infecti#e sta'e> Metacercariae(of fresh/brac>ish

water fish)S

dultS

9i!es in smallintestine

ia'notic> e''s in feces


S8ar ,ast" iberia"

Manchuria" 2la>ans"5sreal" pain

S+eser!oir hostsdogs" cats" fish#

eating mammals birds in endemic

areas

Egg = D

Intestinal:b painDiarrhea

,ggs that migrate to@eart or 2rain D**7 usually cause

symptoms

Pra:iNuant5mpro!edsanitation

pre!entcontaminatio

food/wate

Control snail


fish

,ara'onimuswestermani

?un' lu7e

Infecti#e sta'e> Metacercariae(of 6rustaceans)?i#es in ?"G


ia'notic> e''s in S&utum


11/11

Session 58 and 59:

Helminths

General/

Transmission

Infective/Dx

Stage

Epidemiology Pathophysiology Clinical Tx/ Preventio

Diphyllobothrium

latum

broad fish

tapeworm

**BOARDS**

D!ph"ll#b#thr!as!s

$ecal/#ral%% !sh

Eggs shed in

waterFish

intermed host

Infective Stage

=Plerocercoidin

raw fishS

dultS

smallintestine

Scandinava, Baltic

States

Foodborne=

raw fish

D ursimost common

in U.S.

Ribbon stage= up to 30 ft

Scolex=2 brothria

Dx: Egg

(anopercular knob) or proglottid

Mild GI distress:

Nausea/Diarrhea

Tapeworm pernicious anemia

(worm absorbs Vit. B12)

DOC= Praziqua

Taenia saginata

beef tapeworm

Infective Stage=

Cysticercus

undercooked

meat

Sdult

Ssmall

intestine

Africa, Mexico,

Argentina

Foodborne= beef

Most common

human taeniid

(flatworm)

10-15 ft. --> common

up to 75 ft.

Scolex= unarmed

Key for ID= 20-25

branches/side of central stem in

proglottid

Dx: egg and proglottid (feces)

Mild GI distress

Hunger pains not common

Human not suitable interm host

DOC= Praziqua

Taenia solium

pork tapeworm

Infective Stage=

Cysticercusundercooked

meat

Sdult

Ssmall

intestine

Worldwide

Cysticercosis most

common CNS

parasitic disease

Foodborne= pig

Fecalborne= Man

(eggs from stool

immediately

infectious )

6-10 ft.--> common

Scolex= armed

branches in gravid segments cysticercosis

egg develops into bladderworm-->

Neurocysticercosis--> seizures &

hemiparesis

Larval dissemination (cysticerci in

retina or vitreous humor)

DOC= Praziqua

for both infectio

Possibly Sx f

cysticercosi

Cysticerci ma

resolve w/ou

antihelminthT

Echinococcus

granulosus

hydatid disease

**BOARDS**

Unilocular hydatid

cyst: protoscolices

and brood capsules

dog eats sheepli!er w/ hydatid

cyst#G adultworm##G eggs in

feces

Infective Stage=

egg (dog feces)

Sdult

S

liver(mostly)and lungs

Endemic in sheep-

raising areas

Definitive host= dog

(most common),

coyote, wolf

3-5 mm long

Scolex= armed

Dx: Protoscolex (cyst)

Hydatid sand protoscolices in

cyst

Xray, CT, ELISA

Cyst may go undetected for 20

yrs

Mechanical damage, toxicity

effects, severe abd pain, necrosis

Ruptured Cyst= 1) 2ndary

echinococcosis (free protoscolices

--> new cysts)

2) Anaphylaxis

Surgery

Albendazole (als

prophylactic

Echinococcus

multilocularis

Multilocular or

alveolar hydatid

cyst= liver

Interm host: rodents,

humans

Definitive host: fox,

dog, cat

Cyst metastasis= grave

prognosis

Cross your fing

Hymenolepis

nana

Direct P2P dwarf

tapeworm

Scolex= unarmed Mild GI distress Praziquante

Hymenolepis

diminuta

rat tapeworm

Int. host= Fleas &

beetles

Infective stage=

cysticercoid

Infections can occur in children Dx: egg(feces) Praziquante

Dipylidium

caninum

2x-pored dog

tapeworm

Infective stage=

cysticercoid

Int. host: Fleas

children who eat

fleas

Scolex= armed

2 segments

Definitive host= dog, cat,

humans

Dx:eggcapsule (feces) Praziquante

Treat dog and f

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High Yield GIT Bacteria and Worms

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